mcs/class/IBM.Data.DB2/IBM.Data.DB2/DB2Transaction.cs

   1
   2 //
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   9 // the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be
  12 // included in all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  17 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  18 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  19 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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  21 //
  22 using System;\r
  23 using System.Data;\r
  24 using System.Runtime.InteropServices;\r
  25 \r
  26 namespace IBM.Data.DB2\r
  27 {\r
  28         public sealed class DB2Transaction : MarshalByRefObject, IDbTransaction\r
  29         {\r
  30                 private enum TransactionState\r
  31                 {\r
  32                         Open,\r
  33                         Committed,\r
  34                         Rolledback,\r
  35                 }\r
  36                 IsolationLevel isolationLevel;\r
  37                 DB2Connection db2Conn;\r
  38                 TransactionState state;\r
  39                 \r
  40 \r
  41 \r
  42                 internal DB2Transaction(DB2Connection con, IsolationLevel isoL)\r
  43                 {\r
  44                         long db2IsoL;\r
  45                         db2Conn = con;\r
  46                         short sqlRet;\r
  47 \r
  48                         isolationLevel = isoL;\r
  49 \r
  50                         switch (isoL) \r
  51                         {\r
  52                                 default:\r
  53                                 case System.Data.IsolationLevel.Chaos:                          //No DB2equivalent, default to SQL_TXN_READ_COMMITTED\r
  54                                 case System.Data.IsolationLevel.ReadCommitted:          //SQL_TXN_READ_COMMITTED\r
  55                                         db2IsoL = DB2Constants.SQL_TXN_READ_COMMITTED;\r
  56                                         break;\r
  57                                 case System.Data.IsolationLevel.ReadUncommitted:        //SQL_TXN_READ_UNCOMMITTED\r
  58                                         db2IsoL = DB2Constants.SQL_TXN_READ_UNCOMMITTED;\r
  59                                         break;\r
  60                                 case System.Data.IsolationLevel.RepeatableRead:         //SQL_TXN_REPEATABLE_READ\r
  61                                         db2IsoL = DB2Constants.SQL_TXN_REPEATABLE_READ;\r
  62                                         break;\r
  63                                 case System.Data.IsolationLevel.Serializable:           //SQL_TXN_SERIALIZABLE_READ\r
  64                                         db2IsoL = DB2Constants.SQL_TXN_SERIALIZABLE_READ;\r
  65                                         break;\r
  66                         }\r
  67 \r
  68                         if(db2Conn.openConnection.autoCommit)\r
  69                         {\r
  70                                 sqlRet = DB2CLIWrapper.SQLSetConnectAttr(db2Conn.DBHandle, DB2Constants.SQL_ATTR_AUTOCOMMIT, new IntPtr(DB2Constants.SQL_AUTOCOMMIT_OFF), 0);\r
  71                                 DB2ClientUtils.DB2CheckReturn(sqlRet, DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, "Error setting AUTOCOMMIT OFF in transaction CTOR.", db2Conn);\r
  72                                 db2Conn.openConnection.autoCommit = false;\r
  73                         }\r
  74                         sqlRet = DB2CLIWrapper.SQLSetConnectAttr(db2Conn.DBHandle, DB2Constants.SQL_ATTR_TXN_ISOLATION, new IntPtr(db2IsoL), 0);\r
  75                         DB2ClientUtils.DB2CheckReturn(sqlRet, DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, "Error setting isolation level.", db2Conn);\r
  76 \r
  77                         state = TransactionState.Open;\r
  78                 }\r
  79 \r
  80                 /// <summary>\r
  81                 /// DB2Connection associated with this transaction\r
  82                 /// </summary>\r
  83                 public IDbConnection Connection\r
  84                 {\r
  85                         get\r
  86                         {\r
  87                                 return db2Conn;\r
  88                         }\r
  89                 }\r
  90                 /// <summary>\r
  91                 /// IsolationLevel property\r
  92                 /// </summary>\r
  93                 /// \r
  94                 public IsolationLevel IsolationLevel\r
  95                 {\r
  96                         get \r
  97                         {\r
  98                                 CheckStateOpen();\r
  99                                 return isolationLevel;\r
 100                         }\r
 101                 }\r
 102 \r
 103                 internal void CheckStateOpen()\r
 104                 {\r
 105                         if(state == TransactionState.Committed)\r
 106                                 throw new InvalidOperationException("Transaction was already committed. It is no longer usable.");\r
 107                         if(state == TransactionState.Rolledback)\r
 108                                 throw new InvalidOperationException("Transaction was already rolled back. It is no longer usable.");\r
 109                 }\r
 110 \r
 111                 public void Commit() \r
 112                 {\r
 113                         CheckStateOpen();\r
 114                         DB2CLIWrapper.SQLEndTran(DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, DB2Constants.SQL_COMMIT);\r
 115                         this.state = TransactionState.Committed;\r
 116                         this.db2Conn.openConnection.transactionOpen = false;\r
 117                         this.db2Conn.WeakRefTransaction = null;\r
 118                         this.db2Conn = null;\r
 119                 }\r
 120 \r
 121                 public void Rollback() \r
 122                 {\r
 123                         CheckStateOpen();\r
 124                         DB2CLIWrapper.SQLEndTran(DB2Constants.SQL_HANDLE_DBC, db2Conn.DBHandle, DB2Constants.SQL_ROLLBACK);\r
 125                         this.db2Conn.openConnection.transactionOpen = false;\r
 126                         this.state = TransactionState.Rolledback;\r
 127                         this.db2Conn.WeakRefTransaction = null;\r
 128                         this.db2Conn = null;\r
 129                 }\r
 130 \r
 131                 /// <summary>\r
 132                 /// Dispose method.\r
 133                 /// </summary>\r
 134                 public void Dispose()\r
 135                 {\r
 136                         if (state != TransactionState.Open) \r
 137                                 return;\r
 138 \r
 139                         Rollback();\r
 140                 }\r
 141         }\r
 142 }\r